package com.yy.controller;

import cn.hutool.core.lang.UUID;
import com.yy.utils.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

/**
 * create by KongFuning on 2022/7/31
 */
/*
* 文件的上传和下载
* */
@RestController
@Slf4j
@RequestMapping("/common")
public class CommonController {

    @Value("${download.path}")
    private String basePath;

    /*
    * 文件上传
    * */
    @PostMapping("/upload")
    public R load(MultipartFile file){
        // file是个临时文件，需要转存到指定位置，否则本次请求后临时文件就自动删除了

        // 原始文件名
        String originalFilename = file.getOriginalFilename();
        // 截取原始文件后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        // 使用UUID重新生成文件名，防止文件名重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + suffix;   // abc.jpg

        // 创建一个目录对象
        File dir = new File(basePath);
        // 判断当前目录是否存在
        if(!dir.exists()){
            // 不存在，需要创建
            dir.mkdirs();
        }

        try {
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }

    /*
    * 文件下载
    * */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        FileInputStream fileInputStream = null;
        ServletOutputStream outputStream = null;
        // 输入流，读取文件内容
        try {
            fileInputStream = new FileInputStream(basePath + name);

            // 输出流，将文件写回浏览器，展示图片
            outputStream = response.getOutputStream();
            response.setContentType("image/jpeg");
            int len = 0;
            byte[] bytes = new byte[1024];
            while((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try {
                outputStream.close();
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}
